While the good folks at dropbox prepare a lion compatible release for us you can run the current version of dropbox by issuing those terminal commands before running dropbox for the time after installing: sudo rm -rf /Library/DropboxHelperTools rm /Applications/Dropbox.app/Contents/Resources/DropboxHelperInstaller.tgz defaults write /Applications/Dropbox.app/Contents/Info CFBundleVersion 2.0